What actually gains space in a small bathroom
Five decisions gain real space in a small bathroom: a wall-hung toilet and basin on a concealed frame, a level-access shower instead of a bath, a fixed glass panel instead of a hinged screen door, a sliding pocket door into the room, and storage niches set into the thickness of the walls. Tiles and colour affect the sense of space far less.
All five are decided at the design stage, before demolition. Adding them to a finished wall is almost impossible without opening it up again.
Start with the soil stack and the dimensions
In a flat, the position of the toilet is nearly always dictated by the building's shared soil stack. Moving the toilet a couple of metres away is not always possible: the waste pipe needs a fall, which means space under the floor or a raised floor. In older Eixample buildings the stacks often sit in awkward corners, and that is the first thing we check on a site visit.
Then come the working dimensions. About 60 to 70 cm of clear space in front of the toilet and basin feels comfortable, and a shower needs enough width to raise your elbows. Draw the plan to scale and mark which way the door opens. On that drawing you can see at once which centimetres are being wasted.
Wall-hung fixtures and the concealed frame
A wall-hung toilet and basin with a concealed cistern leave the floor clear. The room looks larger and the floor underneath is cleaned in one sweep. The cost is a false wall for the frame, which takes 15 to 20 cm of depth.
Those centimetres can be won back. The top of the false wall becomes a shelf, and pipes that used to run exposed along the wall disappear inside it. The flush plate doubles as an access hatch to the cistern, so nothing has to be broken to service the valve. The frame must be fixed to a wall or floor that can take the load; on an old hollow-brick partition it only goes in after that has been checked.
A shower instead of a bath, glass instead of a door
A bath takes up around 1.2 m² and gets used less than people think. A level-access shower with a linear drain visually continues the bathroom floor, so the room reads as one space. Technically it needs depth for the trap and a fall towards the drain. If the floor slab does not allow the waste to drop, the whole bathroom floor is raised by a few centimetres and the threshold is detailed to suit.
A hinged shower door needs an opening arc. A fixed glass panel with no door works when the shower area is long enough to keep water in, usually from 100 to 120 cm. Clear glass with minimal framing does not divide the room; frosted glass and heavy frames do.
The door and storage inside the wall
A door opening inwards into a small bathroom sterilises a piece of floor that nothing else can use. A sliding door running into a pocket inside the partition frees that area completely. The pocket frame goes in before plastering, and that stretch of wall can then carry no sockets or pipes.
Storage is best recessed. A niche in the shower wall for toiletries, a mirror cabinet set into the false wall above the basin, a slim cupboard above the concealed frame. Niches in load-bearing or external walls are not cut without checking first: in the first case it is a structural question, in the second one of insulation and condensation.
Light and finishes: what works and what does not
Large-format porcelain with few joints and the same finish on floor and walls remove visual clutter. Light above or around the mirror, combined with general ceiling light, works better than a single bright fitting: your face is lit without shadows and the corners do not sink into gloom.
On the other hand, small dark mosaic on every wall, a bulky vanity standing on the floor and protruding shelves above the toilet eat into the sense of space even with a good layout. We cover ventilation and damp in a separate article; here one rule is enough: without extraction that works, a small bathroom is the first room to deteriorate.
Mistakes that cost money
The typical mistakes repeat themselves. The concealed frame is decided on after tiling. The glass is ordered before the door has been settled. A niche is cut into an external wall and mould appears within one winter. The drain is chosen without checking the depth of the slab. Each of these can only be put right by taking finished work apart.
That is why in our projects the bathroom is designed together with the overall layout of the flat, not afterwards. If your home has only one bathroom, think from the start about how you will live during the works as well.